Color marking stainless steel with fiber laser - best frequency settings?

I recently got a 30W MOPA fiber laser and I'm trying to achieve color marking on stainless steel. I've seen some beautiful rainbow effects but my results are inconsistent.

What frequency and pulse width combinations work best for specific colors? Any tips for getting consistent results across a larger surface area?

Color marking on stainless is all about oxide layer thickness, which is controlled by heat input. Here's what I've found:

For Blues/Purples:

• Lower frequency (20-40kHz)
• Longer pulse width (200-300ns)
• Multiple passes at lower power

For Golds/Yellows:

• Higher frequency (60-80kHz)
• Shorter pulse width (50-100ns)
• Single pass, moderate power

The key is consistency in your scanning speed and hatch spacing. Even small variations will show as color shifts.